1. Technical Field
The present invention relates to a semiconductor light emitting element.
2. Related Art
In recent years, a flip-chip bonding (FC) mounting technology, in which a growth substrate side opposite to an electrode formation surface is provided as a main light extraction surface, has been developed. For example, in Japanese Patent Application Laid-Open Publication No. 2010-263016, there is described a semiconductor light emitting element that includes a substrate composed of sapphire, a laminated semiconductor layer including an n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer and laminated on the substrate, a positive electrode formed on the p-type semiconductor layer and a negative electrode formed on the n-type semiconductor layer, and is mounted by flip-chip bonding.
Incidentally, in the semiconductor light emitting element, when a voltage in which the p-side electrode formed on the p-type semiconductor layer is at the high potential and the n-side electrode formed on the n-type semiconductor layer is at the low potential (a forward voltage VF) is applied, a current (a forward current IF) heading toward the n-side electrode from the p-side electrode through the p-type semiconductor layer, the light emitting layer and the n-type semiconductor layer is passed, and thereby light of the target light emission wavelength is outputted from the light emitting layer. Then, in the semiconductor light emitting element mounted by FC, the light outputted on the electrode formation surface side from the light emitting layer is reflected by a reflecting surface provided on the electrode formation surface side, to be thereby extracted from the growth substrate side opposite to the electrode formation surface.
In the semiconductor light emitting element mounted by FC, it is preferable that the entire surface of the chip uniformly emits light with the light extracted in the direction of the growth substrate side. However, there are some cases in which light emission becomes non-uniform due to the number of electrodes formed on the electrode formation surface side or arrangement thereof. For example, if the n-side electrode is provided at the center portion of the chip and the p-side electrode is provided at each of four corners of the chip, there occurs a problem that light emission is concentrated at the center portion of the chip, and thereby light emission efficiency is lowered, and further, another problem that the chip is apt to be damaged in the electro-static-discharge (ESD) inspection, which is different from uniformity or efficiency of light emission, arises.
It is an object of the present invention to solve a problem that light emission is concentrated at the center portion of the chip, and accordingly the light emission efficiency is lowered, and a problem of ESD damage withstanding voltage in the FC (flip-chip) mounting technology of the semiconductor light emitting element.